SAN FRANCISCO (CBS SF) — A man was arrested on Saturday after allegedly attacking and seriously injuring another man who had apparently urinated on his carpet in San Francisco’s Bayview District, police said.

The attack was reported at about 1:40 p.m. Saturday in the first block of Matthew Court, where officers found the 20-year-old victim lying unconscious on the sidewalk with serious head and facial injuries, police said.

The victim was taken to San Francisco General Hospital to be treated for injuries that were initially considered life-threatening. However, he was later upgraded to stable condition, police spokesman Officer Gordon Shyy said.

The suspect fled the scene after the shooting, but police used surveillance video in the area to identify him and take him into custody in the first block of Ardath Court, Shyy said.

Demarea Barnes, 23, of San Francisco, admitted to knowing the victim and said the fight stemmed from the victim urinating on his carpet instead of in the bathroom, police said.

Barnes was booked into custody on suspicion of assault with a deadly weapon, according to Shyy.

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